Crushed abrasive particles are formed by mechanically crushing abrasive mineral. Due to the random nature of the crushing operation, the resultant particles are typically randomly shaped and sized. Ordinary, initially produced crushed abrasive particles are sorted by size for use later use in various abrasive products and applications.
Within a given distribution of crushed abrasive particles there will be a variety of sizes and shapes. Size sorting is typically carried out by sieving (i.e., using standard mesh sizes) and/or air classification methods, for example.
Shape sorting, typically to isolate large aspect ratio abrasive particles is more complicated and known methods such shape sorting tables and tweezers are impractical for large volumes and have been used generally only for expensive abrasive particles such as, for example, diamond (which are not crushed abrasive particles). In general, high aspect ratio particles, especially if oriented, exhibit superior abrading performance as compared to blockier shapes.
It would be desirable to have a method of shape sorting abrasive particles to improve their average aspect ratio that could be inexpensively carried out for large volumes of abrasive particles, preferably in a continuous manner.